Eat more fat. Yes, I said it

As the fat vs sugar debate rumbles on Nina Teicholz, author of The Big Fat Surprise, explains why doctors have been wrong about our diets all along…

Sep 5, 2014

It seems impossible that nutrition experts could have made such a mistake on the subject of saturated fat. According to two large meta-analyses in recent years, the fats in butter, meat, cheese, and eggs can't be shown to cause heart disease.

This conclusion is a stunning reversal of our most central piece of dietary advice for half a century. How could have our health authorities have got it so wrong?

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The fact is there's never been solid evidence for the idea these fats cause disease. We only believe this to be the case because nutrition policy has been derailed for decades by a mixture of personal ambition, bad science, politics and bias.

Our distrust of saturated fats can be traced back to the 1950s, when the idea that saturated fats clog our arteries and cause heart disease was first suggested. The public, panicked about this killer disease, was receptive. By 1961, the American Heart Association had published its very first dietary guidelines telling people to cut back on saturated fats.

But the evidence this was based on was flawed from the start. The data used to support the guidelines examined nearly 13,000 men but measured the diets of fewer than 500 of them – hardly a representative sample. Some of the men were studied during Lent, when meat and cheese were strictly avoided.

Countries were also cherry-picked, including Greece and Italy, which were likely to prove the saturated-fat theory. Those such as France and Switzerland – home of omelette- and fondue-eaters, which were likely to disprove it, were ignored. Even so, the results influenced expert opinion about fat and heart disease for decades to come.

Of course, other studies ensued. But these trials also had serious problems. Some didn't control for smoking, for instance. The results were therefore unreliable at best. But already so much money and energy had been invested in the idea that Fat Is Bad that there was no turning back – and any data that went against this idea was ignored. The idea that red meat and cheese were damaging to health started to seem like common sense.

By the 1980s, America had exported its low-fat diet around the world. In Scotland, one doctor and researcher led an attempt to resist the influx of American thinking on nutrition, writing in the Lancet, "all my farmers' instincts lead me to suppose that a natural product like butter is likely to be healthier than an artificial product such as margarine."

In fact the first documented heart attack in Scotland was in 1928, just as margarine was being introduced. And some of the longest-lived people in the world in at the time were Irish dairy farmers, eating mainly whole milk, cheese, cream, eggs and lard.

The low-fat diet has beentested more than any other diet in the history of nutrition science, and the results clearly show that it has been a failure. In 2006, the results of a study of 50,000 women found that cutting back on fat didn't improve outcomes for heart disease or diabetes – and women on the diet emerged, on average, 1lb lighter.

Part of the problem is that foods low in fat are almost inevitably higher in carbohdyrates (a low-fat yoghurt, for instance, is higher in sugar). Also, fat with protein is a uniquely satisfying combination – it's hard to overeat on these foods. Bottom line: fat does not make you fat. Cutting back on fat of any kind does not benefit health.

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Now scientists have reappraised those early, flawed studies, conventional wisdom about saturated fat may be changing for good. History and science are aligned on the side of saturated fats. And with butter sales already skyrocketing, you can bet this shift will be a keeper.

The Big Fat Surprise: Why Meat, Butter, and Cheese belong in a healthy diet (£14.99, Scribe) is available to buy here

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